Land mine



R. H. PASS Aug. 23, 1949.

LAND MINE Filed June 22, 1944 Syvum/vm@ Ri Dhurd H. Puaa Hummm Patented Aug. 23, 1949 2,47'siis6i LAND MiNr;

Richard H. Pass, Syracuse, Nf. Y.,

Onondaga Pottery' Com a corporation of New York y Application'Ju'ne 22, 1944, SeialfNo'. 541,619 f,

14 claims.

This invention relates to an explosive landmine and'has'for one of its objects the provision of a generally improved and more satisfactory mine of the land type.

Another object of the invention is the provision oi a mine constructed entirely of nonmetallic material, so that its presence cannot be detected by the usual types of magnetic or electrical detecting devices.

Still another object is the provision of amine so designed and constructed as to be set 01T by sustained weight ofa predetermined amount, and yet not to be set off or damaged by non-sustained pressure caused by suddenl blows (as by" certain types of mine-explodingv apparatus, for example) o1 by adjacent explosions.

A further object is the provision of a, mine of relatively light weight, which may be easily and quickly installed in place.

A still further object is the provision ofamine soshaped and proportioned that even if placed on the surface of the grounderather than buried therein, it is relatively stable against tippingrand thus remains effective against tanks or other vehicles driven over it.A

Other objects of the invention will be apparentfirom the detailed description which follows, whichv description and the `accompanying drawings vare* merely exemplary and are not intended to limit4 the invention to the speciiic construction described.

In the drawing: Y

Figure 1 is a top plan view of amine constructed according to the preferred embodiment of. the invention, with the safety ring invplace andthe fuze in safe or unarmed position; Y

Figure 2 is a vertical section through the same, taken substantially on the line 2 2 of Figure 1: and

Figure 3 is a side elevation-of theV mine with parts brokenfaway and parts in vertical section', showing the safety ring removed andY thefuzein armedposition. Y

The same reference numerals throughout the several views of the drawings indicate the same parts Referring now to the drawings and particularly. to Figure 2 thereof, the mine in its preferred formlcomprises `a main body l| of inverted cup shape, circular in horizontal cross section,v con.. structed of rigidY nonmetallic materials, preferably ofa lceramic nature such as vitreous china or porcelain, or glass, it being intendedto include all of these substances within the broad term "ceramic material as hereinafterV used. At its 'V top; thefbody; hasacentral opening internally threaded; into'` whichY c is screwed an annular adapterV `l3nt nonmetallic material such as moldedy plastic material (Bakelite or some similar molded plastic) externally threaded to engage the threa ols oiv the bodyv il, and internally thread'- ed to receive external threads on the iuze, as described below. Y l y Thebottom edge of the body Il has an annular stepped shoulder, as shown, in which is seated the marginal edge of! a diaphragm or partition I? of4 suitable nonmetallic material, vsuch as a disc ofl'iardpressed` fiberboard, for example. The edges of4 the diaphragm llA are lcemented tightly to vitsfseat inthe body b`y suitable cement indicated atl |9such as calcined gypsum cement, for example. 1n axial alignment with the opening through `the adapter |3 there is an annular groove inthe top surface ofthe diaphragm I7', and inthisannular` groove is seated and cemented the lower end of av hollow cylindrical member or sleeve 21|-, the upper endcf which is seated in an annular step formed in the adapter I3. This sleeveZ l'islikewise of suitable non-metallic material such as molded plastic material, or laminated paper treated with plastic material such asalielite.-l

Within the cavity or space inclosedrbetween the-body Itandthe diaphragm I1, externally of the sleeve 2i, are the explosive elements of the mine. These may be of -anysuitable known composition .or ingredients, such for example as an annular booster pellet'25 of tetryl, surrounding or partially surroundingthe sleeveY 2|, andV a chargefZl of TNT or tetrytol or other suitable high explosive, filling substantially the rest of thelannular space around the sleeve 2| and between the body Il and the diaphragm I1. The main explosive charge may be introduced througha filling openingA 29VV formed in the upper part of the body VH andrlater filled with a suit-Y able plug 3i of plastic cement, for example. c

Beneath and spaced iromthe diaphragm l1 is a-basev 35, Apreferably of ceramic material in the form oa circular atdiscwithaslightly raised marginal rim-on` itsupper surface, as shown. Interposedbetween thebase S55-(and the diaphragm il is -la substance normally spacing these two elementsyat a. predetermined distance from each other, vbu t capable of compressing under the influence-vofsustainedlpr'essure, to enable the base and .theY diaphragm to move closer-to each other. It ifsimportant thatV this-'spacing material offer relatively great resistance to compressionby pressureof instantaneous duration, such as that check, being relatively insensitive to sudden blows without sustained load, but being vsensitive to sustained pressure. The preferredmaterialhaw ing these characteristics is an annular ring 31 of synthetic sponge rubber, the topsurnfacepf the ring being cemented to thebottom of the dia,-

phragm I1 and the bottom surface of the ring' being cemented to the top ofithesbase. 'Rest-,- ing on the top of the base 35 at the center thereof, is the head of a pressure pin 4I of molded plastic material, having a shank extended upwardlythrough and freely -slideablein va central opening in the diaphragm 'I-1. A flexible strap 43 -oi" fabric or other suitable nonmetallic material overlies the shoulder v'between the shank and the vvhead of the pin 41| and hasits ends eemented tothe upper Ysurface of the base'l35, thus holding'the pressure ypin in place. Y

The space between the diaphragm SI1 and the base 35 is sealed laterally bya watertight exible band 5I vof synthetic-rubber, for example, wrapped circumerentially around-the body l I and base v35 and cemented to both of them. 'This band 5| is sufiiciently flexible so that the free unsupported portion thereof bridging the space between the bottom of the body .IVI andthe top Aol the base -35 may readily buckle'when axial pressure causes the body and base to vtend to move toward each other, and Vvtheband may also bulge inwardly or outwardly due to changes yin temperature ofthe air -entapiled in the mine lwithin the band 5I, thus substantially equalizing the air pressure within the mine with the external atmospheric pressure.y

A protective -covering or jacket encloses the mine to guard jit against damage fby accidental dropping vor minor blows. This `jacket maycomprise Va lower cup-shaped section andan upper cup-shaped section. The -lower section includes a plurality of layersA 55v of vsomewhat resilient material lsuch -as asphalt-impregnated soit felt (either `paper -fe'lt or hair felt), and an outer covering 51 'of asphalt-impregnatedhard pressed felt. The inner layers `55 extend racross the bottom-of the base 3'5 `and up the side Vedges thereof approximately to the ylevel of the-top of the base, as shown, but 'do ynot `extend 'above this -level in order -to 'avoid interference with such #outward bulging of the flexible -band 5I asfmayfbe neces'- sary in case the Iair pressure within-the mine tends to rise. 'The outerlayer 51,l1owever, lextends vupwardly a substantial distance above the inner layers 55 'and overlaps the vlower portion of the body I I, as shown.

The upper section of the protective covering or jacket iis similarly formed :by a plurality of layers of soft 'resilient material 6I similar -tothe layers L55, and an outer layer 63similar to the layer 51. v'Ihe1layers fi-I andI3` coverthe top of the body II, except for the Acentral part thereof and Yexcept for the lvicinity of the'lilling 'opening '29, and extend part-way'downtheside lwalls of the body 'I I, the inner 'layers '5I l stopping near thetop 0f the sidewalls andthe/router layers 6'3 continuing downward Ito a l'level somewhat Yabove the top edge ofthe '1ayer`51of thebottom-section of the jacket, leaving a gap 65 between the upper and lower jackets so that the jackets will not interfere with the movement of the base 35 and the body II toward each other, when 4axial pressure is applied to the mine.

A layer of adhesive tape 1I, of a non-hygroscopicnature, lis wrapped circumferentially aroundthe upper and lower jacket sections and overlaps both of them, thus holding them to- .gether Around this is a carrying strap 13 of 'textile webbing having a loop 15 forming a handle.' Another adhesive tape 11, wider than the strap 13, extends part-way around the circumference of the mine, overlapping the carrying strap I3 r.exceptrat the handle portion thereof,

and a short section of adhesive tape 19 extends `axially ofthe'mine, across the carrying strap 13,

inside the handle loop 15. The tapes 1I, 11, and

`19 together with the strap 13 are suiciently flexible so that they buckle readily when axial pressure l.is applied -to compress the member 31 and to-movethebase 135 and body I I toward each other, ywithout adding `substantial resistance to such movement. Another piece of adhesive'tape preferably covers the sealing plug 3l of the fillingA opening y219.

Vivli'fter'the mine-hasbeen loaded with the booster pellet 125, thefadapter fI3 is screwed into place and sealed by plastic bituminous sealing substance 8*! around the marginal edges of the adaptenfsimllar to the sealing substance 3l which ls'later placed inthe filling opening 29 when the main explosive charge has been loaded in the mine. The sealing ring E3 'is -inserted over the topfoftheadapter I3', the marginal edges of the ring 813 resting upon and Vbeing cementedjto the toppf the body 'I I. This sealingring 83 is conveniently'ma'deof reclaimed or synthetic sponge rubber and the periphery lthereof substantially meets theedges of the layers 5I and 53 of the covering jacket, any slight space between Ithem being filled with bituminous plastic cement or sealing-compound Placed on and cemented to the top of the adapter I3, vsurrounding the threaded opening therein, is a gasket Y81,'preferably of cork composition or synthetic rubber or a combination of both. lIfhe lfuze to 'be used with this mine has afheadfQI threaded'to engage the threads in the adapter 13,' the head having atop flange 93 which is of substantially the same diameter 'as the central opening inthe sealing ring '83, and Which-when 'vfully screwed down into effective operating position, rests tightly against the gasket 81 and substantially lls the entire central opening in the sealing ring 83.

' mine in safe or unarmed position, a safety ring ,I'Ilfl 'is placed around the head'of the :fuzeunder the flange 9 3. This ring may be made of any suitable material, metallic or nonmetallic. If metallic, it must be removed from the vicinity of 'the rnine when `the mine is finally installed, so as `to leaye n otmetalxwhich might be detected byY sensitive 4electrical or 'magnetic detecting means 'in the bands of Ythe -enemy- Preferably '75 the safetfringds -of nonmetallic "material such as rubber, inwhich event it need-notte removed far from the'minewhen the mine isinstalled, and it may be conveniently tied tothe mine as for example lby a nonmetallic string or cordV |03, so as to be readily available for use if and when it is desired to disarm and take up'mines previously planted. I

In either event, whether of metallic ornonmetallic material, the safety ring IUI is preferably made sufficiently stretchable or resilient so that, when the head 9| ofthe fuze is slightly unscrewed to release the pressure on the safety ring, the safety ring may be pulled oil right over the flange 93 of the fuze, expanding or stretching suiiiciently to enable this. The function of the safety ring is to forma blocking member or abutment preventing the fuzev from being screwed far enough into-the adapter I3 to bring the ring pin 91 into the range of travel ofthe plunger 4I. With the safety ring IUI in place, the ring pin 91 is maintained in a suiciently elevated position so that the plunger 4| cannot come into contact with it. The shoulder of the enlarged head of the plungerl 4I will contact with the bottom surface of the diaphragm I1, before the upper end of the plunger meets the ring pin 91. This, of course, is not true when the safety ring IIJI is removed, for then the head 9| of the fuze can be screwed down into the adapter I3 far enough-so that a slight upward movement of the plunger 4I relative to the diaphragm I1 and body II will cause pressure on the lower end of the ring pin 91. and willre the fuze, which in turn will explode the mine.

In some instances it may be desired to install in the mine a second fuze, so constructed as to fire the mine if it is lifted from the position in which it has been planted by one unacquainted with the installation, the mine thus forming what is commonly knownV as a booby trap, in addition to its main function of serving as a mine set oif by a tank or other vehicle passing over. To enable installation of such second fuze device, the base 35 may be provided, slightly eccentrically, with a threaded opening |2I normally .a

closed by a threaded plug |23 of molded plastic material. Aligned axially with this opening I2I is an opening in the diaphragm I1, from which opening rises a small tube |25 cemented to the diaphragm |1 and made of solid or laminated plastic material. The upper end of the tube |25 contains a detonator |21 of any suitable detonating material such as that commonly known as PETN.

If it is desired to install the anti-lifting device, the plug |23 is removed anda fuze of suitable known type, forming no part of the present invention, is screwed into the threaded opening I2I, the fuze parts being of tubular form extending upwardly into the tube |25. Such a fuze, as well understood' in the art, can be so arranged as to be activated upon any attempt to lift the mine from the position in which it is planted. If such a fuze is not desired at any particular installation, the plug |23 is left in place when the mine is planted, instead of being removed.

The installation of the mine and its action may be summarized as follows:

When a loaded but unfuzed mine reaches the vicinity where it is to be used, a fuze is inserted by screwing the head 9| of the fuze partly into the threaded opening in theA adapter I3, the safety ring I0| meanwhile being aroundl the head of the fuze, beneath the'ange 93, as shown in Fig. 2. This safety ring prevents the fuze from being screwed far enough into the adapter to bring the ring pin 91 into the range of travel of 'the plunger 4l, even when the plunger is moved inwardly to its maximum extent (that is, with the flange of the plunger seated against the under side ofthe diaphragm I1), In this condition, the mine is substantially safe even against rough handling. The felt jackets 55, 51, 6I, and 63 protect the mine (particularly the brittle ceramic parts II and 35 thereof) from damage if handled roughly or even if dropped several feet onto a hard surface such as a concrete roadway. The mine, in this safe condition, is carried by the carrying strap or handle 15 to the position where it is to be used, and ordinarily is buried in the ground with its top surface approximately flush with or slightly below the ground level, and with a light sprinkling of dirt over the mine. The safety ring IRI in combination with the seal 83 keeps dust or dirt from entering the mine while it is being inserted in the ground and while dirt is being filled in around it.

When the mine has been placed in the ground and dirt filled in around it, the fuze 9| is unscrewed a turn or two, enough to loosen the safety ring IUI, which is then pulled right oil? the top or head of the fuze, over the flange 93, the resilient ring expanding enough to permit this. Then the fuze is screwed home into the mine, from the safe position shown in Fig. 2 to the armed position or effective position shown in Fig. 3, wherein the top of the fuze is approximately ush with the top of the sealing ring 83 and in peripheral contact therewith. In this lower Vor armed position of the fuze, the firing pin 91 at the bottom of the fuze lies just above the top of the plunger 4I, in position to be contacted and moved by slight upward movement of thev plunger relative to the body Il and diaphragm I1 of the mine. A sprinkling of dirt is then'placed over the entire top of the mine, which completesl the installation, The safety ring IBI and its attaching cord |03 are, of course, either removed entirely and carried away, or buried in the hole beside the mine.

If a tank or other vehicle passes over the mine, the weight thereof presses downwardly on the top of the mine, this pressure causing compression of the resilient member 31 so that the entire upper portion of the mine (body I I, diaphragm I1, and all parts mounted thereon) moves downwardly toward the base 35. This relative movement of the upper and lower parts toward each other causes the plunger 4I to project farther into the upper part of the mine, contacting with and causing upward pressure on the firing pin. If the pressure exerted on the mine by the vehicle or other object passing over it is sufliciently great, there will be suiiicient upward force on the firing pin 91 to actuate the fuze, which will produce an explosive force (as well known in the art) sufficient to set off the booster pellet 25 and this will explode the main explosive charge 21. By manufacturing the compression ring 31 of different dimensions, the pressure at which the mine will explode can be varied.

Although the mine is extremely sensitive and effective with respect to any pressure exerted for an appreciable length of time, such as by a vehicle passing over it, yet the mine of the present invention is very insensitive to a momentary or instantaneous blow not followed by sustained pressure. This is an extremely desirable characteristic constituting a substantial advance over contact with and be actuated by said actuating member when the fuze is seated in eiective position, and a removable safety member limiting the extent to which said fuze may be inserted in said first-mentioned opening to hold said fuze in a position out of the limited range of travel of said actuating member.

6. In an explosive device, the combination of a body having a threaded opening therein, a fuze actuating member having a limited range of travel within said body, a fuze including a threaded portion to be screwed into said threaded .opening in said body and also having an enlarged head exteriorly of said body, and a removable safety device comprising a resilient member arranged, when in safety position, to surround said fuze exteriorly of said body and underlying said enlarged head, to limit the extent to which said fuze may be screwed into said body in order to maintain said fuze out of the range of travel of said actuating member, said safety member being adapted to be removed to permit said fuze to be screwed farther into said body to bring said fuze within the range of travel of said actuating member.

7. A nonmetallic mine comprising a generally cup-shaped hollow nonmetallic body open at one side, a partition of nonmetallic material extending across and substantially closing said open side, a plate of nonmetallic material substantially parallel to said partition and spaced exteriorly therefrom, a resilient annular ring interposed between said partition and said plate and resiliently tending to hold them at a predetermined distance from each other, said ring being capable of deformation under the influence of sustained pressure to allow said plate and said partition to move closer to each other, an opening in said partition, and e. fuze actuating member associated with said plate and having a portion extending through said opening into said body to actuate a fuze located therein when said partition and said plate move toward each other to a predetermined extent- 8. A construction as described in claim 7, further including a flexible band of relatively thin, rubber-like material extending around the perimeter of both said body and said plate, bridging the space between them and sealed both to said body and said plate.

9. A construction as described in claim 7 further including a flexible sealing band extending around the perimeters of both said body and said plate to inclose the space between them in a substantially airtight manner, and a shock-absorbing jacket of felt-like material having a part covering a substantial portion of the outer surfaces of said body and said plate to protect them against damage by blows, said jacket being out of contact with at least a substantial portion of the area of said flexible band to permit said band to bulge outwardly without interference by -said jacket, if air pressure within said mine tends to rise above the surrounding atmospheric pressure.

10. A construction as described in claim 7 in which said nonmetallic body is made of ceramic material.

11. A construction as described in claim 7 in which said plate is made of ceramic material.

12. A construction as described in claim 7 in which said partition is made of brous material.

13. A construction as described in claim 7 in which said body and said plate are both made of ceramic material and in which said partition is made of fibrous material.

14. A construction as described in claim 7 in which said annular ring is of relatively thick cellular rubber-like material so placed as to be compressed by movement of said plate and partition closer to each other under the influence -of pressure.

RICHARD H. PASS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,375,522 Campbell May 8, 1945 2,376,332 Adelman May 22, 1945 2,429,246 Traylor Oct. 21, 1947 FOREIGN PATENTS Number Country Date 16,192 Great Britain June 21, 1906 326,236 Germany Sept. 25, 1920 750,351 France May 22, 1933 777,331 France Nov. 26, 1934 

